China's rapid military buildup and increasing assertiveness in the seas and skies made 2014 a "year of growing risks to security" in East Asia, the Defense Ministry's core policy arm said Friday in its annual report.

"As the United States continuously plays the leading role in keeping the regional security order, it will be a critical task for neighboring countries to support regional peace and stability by urging China to conform with the international order based on international law and norms as well as to play a responsible role in the framework of free global economy," the National Institute for Defense Studies said in the report.

The East Asian Strategic Review for 2015 listed the confrontations between China and Vietnam over maritime resource development and territory in the South China Sea as one example of growing risk.